The safe excavation of buried radioactive waste is very difficult because highly radioactive material may be dispersed and released to the air. In the past, excavation of low-level radioactive material has often been performed inside closed temporary buildings, with workers wearing protective suits and digging with tools. This can be a very labor-intensive process, and workers are protected only by protective gear and strict adherence to decontamination procedures. Excavation of very large sites could take decades to complete and require hundreds of thousands of man-hours of workers exposed to these hazards. Some waste releases large amounts of highly penetrating radiation, requiring handling by remote means. With such highly radioactive waste, conventional excavation processes might not be feasible because a protective suit might not protect the worker from the more intense radiation.
The United States Government has buried vast amounts of radioactive waste in unlined holes in the ground. Certain waste from the federal government's production of nuclear weapons is transuranic, remaining radioactive for many thousands of years. This transuranic waste may be only slightly radioactive and very hard to detect, or highly radioactive, but it still remains so for a very long time. In many cases, the federal government has entered into agreements with state and local governments that it will remove waste that is classified as transuranic from the burial sites and place the waste in specially designed facilities, such as in a salt dome or inside a mountain in another state. Removal can be difficult, however, once the waste has been buried in the ground with other non-transuranic waste in mixed layers, often up to 20 feet deep. In many cases, records may have been lost or may be incomplete. Determining what is transuranic and what is not may require digging it all up and placing it in special detection instruments.
Some transuranic waste is known to be self-dispersing due to the energetic alpha particles that essentially knock radioactive particles off the surface and create airborne dust spontaneously. Therefore, over time the interior of any building or container where the waste is stored or exposed to atmosphere may become contaminated with particles that can be hazardous to workers.
Waste at these landfills is commonly comprised of contaminated soil and debris. The debris often includes cardboard boxes, wooden crates, carbon steel drums, and other solid objects. The cardboard boxes as well as the drums are potentially decomposed to an extent that they may rupture if disturbed. The waste may contain larger pieces of debris made of metal, wood, or concrete. In some sites, large pieces of machined beryllium metal from the core of a nuclear reactor are buried. These objects may be as large as a refrigerator, highly radioactive, and contain traces of transuranic materials.